JackOfAll;572163 Wrote: > There has been quite some discussion about HDTracks and upsampled files > over at the 'Audio Asylum PC Audio forum' > (http://www.audioasylum.com/forums/pcaudio/bbs.html). A quick search > should find the relevant threads. More than a few hi-res recordings > have been ripped from SACD's that were themselves upsampled from > 16/44k1 CD's. There are plenty of SACD releases out there that are > nothing more than upsampled CD's. > > Also bear in mind that the track I chose to use to demonstrate had > plenty of high frequency content up to 44K1 (half the 88k2 sample rate) > so it shows the brickwall effect very well. > > There are plenty of high-res recordings that don't have much if any > high freq above 20K. Could be for many reasons, not necessarily digital > brickwall at half the original sampling rate. eg. analogue low pass > filter. Or some of the Linn recordings that are advertised as 192K, > were "mixed" at 96K then "mastered" at 192K. (But they clearly state > that.) Even when HF content is present, in some cases it is not > obvious. Someone with experience like BruceB can look at the high > frequency content and differentiate DSD aliasing artefacts from real > content. Which I believe he is now doing for all the SACD rips he does > for HD Tracks after the "upsampling != high res" bruhaha.
Correct me if I'm wrong, but I think that the only well defined case is the following one : You downsample a high resolution file, then upsample to the original sample rate, which gives you the very same, binary identical, original file. In that case, you are sure that there is no more information in the high resolution file, than in the downsampled one. Otherwise you can say nothing. I think it is easy to write a software which upsample a file, and mix it with high resolution noise, or whatever kind of "reverse dithering" dsp. This will add artificial high resolution data you can hardly distinguish from real high resolution recording. -- nicolas75 ------------------------------------------------------------------------ nicolas75's Profile: http://forums.slimdevices.com/member.php?userid=15823 View this thread: http://forums.slimdevices.com/showthread.php?t=74688 _______________________________________________ Touch mailing list [email protected] http://lists.slimdevices.com/mailman/listinfo/touch
